The objective of this research is the devlopment of a methodology based upon confirmation parameters which provide criteria for assessing prehospital EMT diagnostic and therapeutic decisions. Cohorts of patients ith cardiac arrest, abdominal/chest trauma, peripheral fractures, and suspected myocardial infarction are the test group at the core of this study. Measurements obtained in the Emergency Room form the basis of the following confirmation parameters: 1) For patients with cardiac arrest, arterial blood pH and lactic acid levels are the confirmation measurements of the effectiveness of cardiopulmonary resuscitation (CPR). Urine specimens are examined for evidence of acute tubular necrosis. 2) For patients with solid organ, vascular or visceral trauma, distribution of the rates of change per unit time for blood pressure, pulse rate, and double product are being correlated with the number of units replaced in the first two hours after arival in the Emergency Room. These rates of change are used to assess the EMT's decision about the relative severity of the patient's condition and the subsequent need for fluid replacement. 3) For patients with peripheral fractures, we are measuring a number of parameters to assess the EMT's recognition and appropriate treatment of fractures. These include: location, evidence of dislocation, type of fracture, treatment performed by the EMT, and evaluation of the splint. False positive and false negative rates of splinting are being calculated. 4) For patients with suspected myocardial infarctions in the opinion of the emergency room physicians, the relative contribution of the 10 Immiment MI (IMIR) symptoms to the false positive and false negative rates of recognition by the EMTs will be assessed. These measurements based on a group of 135 graduates of the national 81-hour EMT course can be used as standards against which the performance of other groups of EMTs in different types of training programs can be compared.